With so much talk about biodiesel fuel, hybrids, and hydrogen powered cars, it may seem like you can't use your old car at all if you're concerned about the environment. While a lifestyle change is probably inevitable for all of us eventually, there are many things we can do until eco-friendly models make our gas-powered cars of today obsolete.

Of course, decreasing how much and how often we drive is the best solution for our ecological conundrum, but since most of us won't give up driving all together, consider the following five easy ways to decrease your car's environmental impact.

Getting your car serviced regularly will help you and the environment. You'll increase your fuel efficiency, decrease your greenhouse gas emissions, and add to your car's life. Getting your oil changed on time is great, but having your car checked for problems regularly is even better. When your car gets checked out, mechanics can spot problems (like a broken thermostat, low transmission fluid, sticky brake calipers, or even a dirty air filter) early on.

If you can't remember when your car was checked out last, take it in. Even if you only increase your mileage by 10%, that's still a difference: a difference that can save you up to $200 in a year, which is more than enough to pay for the inspection.

A friend of mine was telling me how he went to a fast food establishment the other day, and after finally reaching the drive-thru microphone after 20 minutes of waiting, he was told the place was closed. So not only did he not get his food, he just spent 20 minutes sending carbon emissions from his car into the atmosphere! Talk about a lose-lose situation.

If he'd skipped the drive-thru, he probably would have gotten better service, and he'd have had lessened his environmental impact. Even if you are pretty lucky when hitting drive-thrus, you're likely still idling more than you realize. If you spend just 5 minutes in the drive-thru for lunch each weekday, that's a total of 1300 minutes, or more than 21 hours, a year!

Believe it or not, by slowing down you're not only more likely to arrive at your destination in one piece, you'll definitely get better gas mileage. Starting and stopping quickly are bad ideas too; studies actually show that accelerating and decelerating abruptly is not only horrible for your fuel efficiency, it increases wear and tear on your car.

Keeping your speeds down even has the math to back it up. Because wind resistance builds up so much with higher speeds, every mile per hour you drive over 55 decreases your fuel economy by 2%. That means, unfortunately, that if you're driving 80 mph, even on the freeway, you've cut your fuel economy by half, which not only hurts the environment, it hurts your wallet too.

Usually cold weather is the best excuse we have to leave our cars idling for 10 minutes. The car needs to warm up, and besides, that ice on the windshield needs to melt before you can drive off, right? Wrong.

As much as we like to jump into a warm car on a cold winter day, the car is perfectly capable of driving off without 'warming up.' The only exceptions to this rule are if you drive an older model car or if your car has been sitting out in sub-zero temperatures overnight. As for your windshield, it might be nice to merely turn on your wipers to clear the melted frost away, but good old-fashioned elbow grease works too. Break out your eco-friendly windshield scraper and scrape that ice away!

If you've heard it once, you've heard it a hundred times: it's not good to be driving around on under-inflated tires. Then again, over-inflating your tires isn't the solution; what you really need to do is buy a tire-pressure gauge and check your tires at least once a week. Why, you ask? Read on, grasshopper.

Under-inflated tires are bad because they increase the friction between your rubber and the road, and all that friction accounts for horrible gas mileage as well as increased carbon emissions. Over-inflating your tires might seem like a solution that won't have you checking your tires quite so often, but, in fact, over-inflating will jeopardize your car's handling and possibly cause a tire blow out. Not a good option.